Electrophotographic element

Abstract

A reusable electrophotographic imaging element having a photoconductive surface layer in which the binder resin comprises a block copolyester or copolycarbonate having a fluorinated polyether block. The layer has low surface adhesion and affords improved transfer of toner images to receiver sheets.

I claim: 
     
       1. An electrophotographic imaging element comprising a conductive support and a surface layer that is either capable of generating and injecting charge carriers upon exposure to actinic radiation or capable of accepting and transporting injected charge carriers, said surface layer having an electrically insulating binder resin matrix which comprises a block copolyester or copolycarbonate having a fluorinated polyether block of the formula,   --CR.sup.1 R.sup.2 --CR.sup.3 R.sup.4 O)hd n(CR.sup.5 R.sup.6 O).sub.m     wherein each of R 1 , R 2 , R 3 , R 4 , R 5  and R 6  is fluorine or a perfluorinated lower alkyl group, n and m are integers and the sum of n plus m is from 10 to 100.   
     
     
       2. An element according to claim 1, wherein the weight percent of the fluorinated polyether block in the block copolymer is in the range from about 5 to 50. 
     
     
       3. An element according to claim 2 wherein the copolymer has a polyester segment which is a complex polyester derivative of one or more dicarboxylic acids and one or more diols, at least one of the acids being an aromatic dicarboxylic acid. 
     
     
       4. An element according to claim 1 wherein the binder resin matrix consists essentially of said block copolymer. 
     
     
       5. An element according to claim 1 wherein the binder resin matrix comprises a blend of polyester or polycarbonate binder resin and said block copolymer in an amount sufficient to provide an amount of the fluorinated polyether block in the binder resin matrix comprising at least about 5 weight percent of the binder resin matrix. 
     
     
       6. An element according to claim 1 wherein the element is a multilayer element. 
     
     
       7. An element according to claim 1 wherein the surface layer contains an organic aggregate photoconductive composition. 
     
     
       8. An element according to claim 6 comprising in sequence a conductive support, a charge generation layer, a first charge transport layer and, as the surface layer, a second charge transport layer. 
     
     
       9. An element according to claim 8 wherein the charge generation layer contains an aggregate photoconductive composition. 
     
     
       10. An element according to claim 9 wherein the surface layer contains a tetraarylmethane or a triarylamine dispersed in the block copolyester or copolycarbonate. 
     
     
       11. An element according to claim 1 wherein the binder resin matrix of the surface layer comprises a block copolyester or block copolycarbonate made by copolymerizing polyester or copolycarbonate monomers with a fluorinated polyether oligomer of the formula,   X--CH.sub.2 --O--CR.sup.1 R.sup.2 --CR.sup.3 R.sup.4 O).sub.n (CR.sup.5 R.sup.6 O).sub.m CH.sub.2 --X.sup.1,     wherein the R groups and n and m are as in claim 1 and X and X 1  are functional groups for condensation reactions.   
     
     
       12. An element according to claim 6 comprising in sequence a conductive support, a charge transport layer and, as the surface layer, a charge generation layer containing an aggregate photoconductive composition.